Multiple tuning system



Aug. 2, 1949. D. B. KElM MULTIPLE TUNING SYSTEM Filed Jan. 21, 1948 Inventor:

m a e n K .P sMm da a A m DM w Patented Aug. 2, 1949 MULTIPLE TUNING SYSTEM Donald B. Keim, Bridgeport, Conn, assignor to 'General'Electric Company, a corporation of New York Application January 21, mas-la No. 3,412

This invention relates to tuning systems for radio apparatus and the like, and more particu- .,larly to an improved means for tuning simultaneously a plurality of electrical circuits.

It is an object of this invention to provide a tuning system for tuning simultaneously a plurality of electrical circuits, which is compact, simple in construction, and wherein the circuits may be tuned accurately and precisely to any desired setting.

It is a further object of'this invention to provide such a multiple circuit tuning system in which the pre-setrelationship between the various circuits being tuned is strictly maintained.

Yet, a further object of this invention is to provide a tuning system which may be utilized to tune simultaneously a relatively large number of electrical circuits.

A still further object of this invention is to provide a tunin system that is rugged in construction and non resilient in nature, whereby the calibration of this system is rigidly adhered to.

Yet another object of this invention is to provide a tuning system for tuning simultaneously a plurality of electrical circuits in which the respective tuning elements of the circuits may be simply and conveniently individually adjusted, for alignment purposes.

The features of this invention which are believed to be new are set forth with particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof may best be understood by reference to the accompanying drawing wherein the single figure represents a preferred embodiment of the invention.

Referring now to the figure, shaft I represents the tuning control of the proposed mechanism. Shaft I may be mounted in any suitable bracket, not shown, this bracket serving as a support for the tuning mechanism. Rigidly mounted on shaft I and rotated thereby is a pulley or roller 2, which in turn drives a further pulley or roller 3 which is mounted on shaft 4, the rollers 2 and 3 being coupled together by means of a metallic strap or ribbon in a form of a belt 5 supported by the above-mentioned rollers. The pulleys may more conveniently be mounted in the position shown with the pulley 2 vertically above pulley 3, so that the one side of the belt 5 travels in an upward direction as the other side travels downward. The belt is secured to pulleys 2 and 3 by way of screws 6, the corresponding screws 6 in pulley 2 not being visible in the view shown in the accompany figure.

5 Claims. (01. 74-103) Crossarms I and 8 are attached to belt 5 on opposite sides thereof by means of rivets 9. Any desired number of circuit elements may be adjustably attached to these crossarms, In the present example three such elements are shown, these elements comprising tuning cores I0 and I I, and a tuning vane I2. The tuning cores I0 and II and the vane I2 are secured to crossarms 1 and 8 by adjustableclamping screws l3 of the split type, and hexagonal units I3. It can be seen that for aligning purposes the various cores and vanes may be individually longitudinally adjusted, and

clamped by means of screws I3.

tuning arrangement having a fixed vane 20 mounted in brackets 21, the brackets 21 being mounted to a chassis.

When the tuning shaft I is turned by any suitable means, the crossarms I and 8 move in diametrically opposite directions and the longitudinal movement of cores I0 and II and vane I2 in their corresponding coils and tuning unit may be utilized to effect tuning of the electrical circuits associated therewith.

In the present system, the diameter of pulleys 2 and 3 determine the length of travel of the various cores and vanes with respect to the rota.- tion of tuning shaft I. It is noted that the diameter of the pulleys 2 and 3 should be large enough to insure full desired longitudinal travel of the tuning elements with less than rotation of the pulleys.

This invention, therefore, provides an improved tuning arrangement in which a plurality of electrical circuits may be tuned simultaneously, and wherein the crossarms I and 8 may be extended to include any practical number of tuning elements for such circuits.

This invention has a further advantage in that the utilization of a metal strap precludes stretching thereof and the mechanism is capable of hold ing its calibration to a high degree of accuracy. Furthermore, the provision of the adjustable clamping screws I3 makes possible the facile adjustment of the individual elements of the electrical circuit for aligning purposes.

While a certain specific embodiment has been shown and described, it will of course be understood that various modifications may be made without departing from the invention. The appended claims are therefore intended to cover any such modifications within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A tuning mechanism for imparting longitudinal motion simultaneously to a plurality of tuning elements, comprising, a driving shaft memberfhaving a roller member mounted thereon, an idler shaft member having a further roller member mounted thereon, a flexible continuous strap coupling said first-mentioned roller mem her to said further roller member, crossarm means mounted on said flexible strap, and means for coupling said tuning .eiements to said crossarm means.

2. A tuning mechanism for imparting longitudinal motion simultaneously to a .pluralityof tuning elements, comprising, a driving shaft member having a roller member mounted thereon, an idler shaft member having a further roller member mounted'thereon, a flexible continuous strap coupling said first-mentioned roller member to said further roller member, a pair of crossdinal motion simultaneously to a plurality of tuning elements, comprising, a driving shaft member having a roller member mounted thereon, an'idlershaft member having a further roller member mounted thereon,'a flexible continuous strap coupling said first-mentioned roller memberto said further roller member, a pair of crossarms mounted on said flexible strap, means for coupling said tuning elements to said crossarms, and means for individually adjusting the longitudinal position of said tuning elements.

bar to said further roller member, a pair of crossarms mounted on said flexible strap, and individually adjustable coupling means for coupling, said tuning elements to said crossarms'.

,5. Inaradio tuning system, a plurality of lik ing circuits wherein longitudinal motion of t 1 iingelements associated with said respective circuits effectsthe-tuning thereof, means for imparting longitudinal motion to said tuning elements, saldzmeans comprising a pair of roller members spaced apart one from the other, a driving shaft and an idler shaft supporting said respective roller members, a continuous flexible strap coupling said roller members, -crossarm means mounted onsaid flexible strap, and means for couplingsaiwtuning elements to'sai'd crossarm means for longitudinal motionofsaid elements in response to rotation of said driving shaft.

DONAIDB. KEIM.

, REFERENCES 1 CITED The following references are of-record'in-the file of this patent:

UNITED ESTATES PA'IENTS Number Name Date 1,968,439 Cousin JulyBl, 1934 2,226,822 Kirk et al Dec.31,,1940 2,260,985 Benton et a1. Oct.128,1941 

